Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate and a second substrate opposed to the first substrate. The first substrate includes an insulating substrate, a switching element located on the insulating substrate and having a relay electrode, an organic insulating film covering the switching element and having a first through-hole penetrating to the relay electrode, a pixel electrode being in contact with the relay electrode via the first through-hole, a first capacitance insulating film covering the pixel electrode, a filler having an insulation property filled in at least the first through-hole and located on the pixel electrode and the first capacitance insulating film, and a common electrode covering the filler.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No.PCT/JP2019/050994, filed Dec. 25, 2019 and based upon and claiming thebenefit of priority from Japanese Patent Application No. 2019-085517,filed Apr. 26, 2019, the entire contents of all of which areincorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

In a display device, each pixel has a storage capacitance for holding asignal potential applied to a display element. Recently, with theincrease of the definition of the display device, there has been demandto reduce the size of a pixel electrode while maintaining the storagecapacitance. In order to increase the storage capacitance, such aconfiguration is known that each pixel comprises three layers oftransparent electrodes stacked on top of each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing the configuration and equivalentcircuit of a display device of the present embodiment.

FIG. 2 is a plan view showing a configuration example of a pixel shownin FIG. 1.

FIG. 3 is a cross-sectional view of a display panel along line A-B shownin FIG. 2.

FIG. 4 is a cross-sectional view of a first substrate along line C-Dshown in FIG. 2.

FIG. 5 is a modification of the cross-sectional view of the firstsubstrate along line C-D shown in FIG. 2.

FIG. 6 is a cross-sectional view showing a detailed configurationexample of a relay electrode RE shown in FIG. 5.

FIG. 7 is a cross-sectional view showing the first modification of thefirst substrate.

FIG. 8 is a cross-sectional view showing the second modification of thefirst substrate SUB1.

FIG. 9 is a cross-sectional view showing the third modification exampleof the first substrate.

FIG. 10 is a cross-sectional view showing the fourth modification of thefirst substrate.

FIG. 11 is a cross-sectional view showing the fifth modification of thefirst substrate.

FIG. 12 is a plan view showing a configuration example of a capacitanceelectrode shown in FIG. 3.

FIG. 13 is a plan view showing a configuration example of a commonelectrode shown in FIG. 3.

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided a displaydevice comprising a first substrate and a second substrate opposed tothe first substrate. The first substrate comprises an insulatingsubstrate, a switching element located on the insulating substrate andhaving a relay electrode, an organic insulating film covering theswitching element and having a first through-hole penetrating to therelay electrode, a pixel electrode being in contact with the relayelectrode via the first through-hole, a first capacitance insulatingfilm covering the pixel electrode, a filler having an insulationproperty filled in at least the first through-hole and located on thepixel electrode and the first capacitance insulating film, and a commonelectrode covering the filler.

According to another embodiment, there is provided a display devicesubstrate comprising an insulating substrate, a switching elementlocated on the insulating substrate and having a relay electrode, anorganic insulating film covering the switching element, and having afirst through-hole penetrating to the relay electrode, a pixel electrodelocated farther from the insulating substrate than the organicinsulating film, and being in contact with the relay electrode via thefirst through-hole, a first capacitance insulating film covering thepixel electrode, a filler having an insulation property filled in atleast the first through-hole, and located on the pixel electrode and thefirst capacitance insulating film, and a common electrode covering thefiller.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges in keeping with the spirit of the invention, which are easilyconceivable by a person of ordinary skill in the art, come within thescope of the invention as a matter of course. In addition, in somecases, in order to make the description clearer, the widths,thicknesses, shapes and the like, of the respective parts areillustrated schematically in the drawings, rather than as an accuraterepresentation of what is implemented. However, such schematicillustration is merely exemplary, and in no way restricts theinterpretation of the invention. In addition, in the specification anddrawings, constituent elements which function in the same or a similarmanner to those described in connection with preceding drawings aredenoted by the same reference numbers, and detailed description thereofwhich is considered redundant may be omitted where appropriate.

FIG. 1 is an illustration showing the configuration and equivalentcircuit of a display device DSP of the present embodiment.

A first direction X, a second direction Y and a third direction Z areorthogonal to each other in one example, but may intersect at an angleother than 90 degrees. The first direction X and the second direction Ycorrespond to directions parallel to the main surface of a substrateconstituting the display device DSP, and the third direction Zcorresponds to the thickness direction of the display device DSP. In thespecification, a direction toward the pointed end of an arrow indicatingthe third direction Z is referred to as an upward direction (or simplyabove) and a direction toward the opposite side to the pointed end ofthe arrow is referred to as a downward direction (or simply below).

The display device DSP comprises a display panel PNL and a wiring boardWB mounted on the display panel PNL. The display panel PNL is a liquidcrystal display panel, and comprises a first substrate SUB1, a secondsubstrate SUB2 opposed to the first substrate SUB1, a sealing materialSE, a liquid crystal layer LC, a signal line S, a scanning line G, aswitching element SW, a pixel electrode PE, a common electrode CE andthe like. In addition, the display panel PNL comprises a display area DAwhere an image is displayed, and a non-display area NDA which surroundsthe display area DA. It should be noted that the display panel PNL maybe a display panel having an electrophoretic element.

The first substrate SUB1 has a mounting portion MA exposed to theoutside from the second substrate SUB2. The sealing material SE islocated in the non-display area NDA, and bonds the first substrate SUB1and the second substrate SUB2 together. An area where the sealingmaterial SE is arranged is shown by hatch lines in FIG. 1. The displayarea DA is located on the inside surrounded by the sealing material SE.The display panel PNL comprises a plurality of pixels PX arranged in amatrix in the first direction X and the second direction Y in thedisplay area DA.

The signal line S, the scanning line G, the switching element SW, thepixel electrode PE, the common electrode CE and the liquid crystal layerLC described above are located in the display area DA. The signal line Sextends along the second direction Y, and the scanning line G extendsalong the first direction X. The switching element SW is composed of,for example, a thin-film transistor (TFT), and is electrically connectedto the scanning line G and the signal line S. The pixel electrode PE iselectrically connected to the switching element SW. Each pixel electrodePE is opposed to the common electrode CE, and drives the liquid crystallayer LC by an electric field generated between the pixel electrode PEand the common electrode CE. A storage capacitance CS is formed between,for example, an electrode having the same potential as the commonelectrode CE and an electrode having the same potential as the pixelelectrode PE.

The flexible wiring board WB is mounted on the mounting portion MA. Inaddition, the wiring board WB comprises a drive IC chip 2 which drivesthe display panel PNL. It should be noted that the drive IC chip 2 maybe mounted on the mounting portion MA.

The display panel PNL of the present embodiment may be any of atransmissive type having a transmissive display function of displayingan image by selectively transmitting light from the back surface side ofthe first substrate SUB1, a reflective type having a reflective displayfunction of displaying an image by selectively reflecting light from thefront surface side of the second substrate SUB2, and a transflectivetype having the transmissive display function and the reflective displayfunction.

FIG. 2 is a plan view showing a configuration example of the pixel PXshown in FIG. 1. A capacitance electrode and the common electrode CE arenot illustrated in FIG. 2. The detailed plan view of the capacitanceelectrode is shown in FIG. 12, and the detailed plan view of the commonelectrode CE is shown in FIG. 13.

Scanning lines G1 and G2 each extend along the first direction X, andare arranged with a space in the second direction Y. Signal lines S1 andS2 each extend along the second direction Y, and are arranged with aspace in the first direction X. The pixel PX corresponds to an areadelimited by the scanning lines G1 and G2 and the signal lines S1 andS2.

The switching element SW is a double-gate thin-film transistor in oneexample. The switching element SW comprises a relay electrode RE, asemiconductor layer SC, gate electrodes GE1 and GE2 and the like.

The relay electrode RE is located between the signal line S1 and thesignal line S2. A part of the relay electrode RE overlaps the scanningline G1. The relay electrode RE has a width W1 in the first direction X.A gap GP1 between the relay electrode RE and the signal line S1 is lessthan the width W1. Similarly, a gap GP2 between the relay electrode REand the signal line S2 is less than the width W1.

The semiconductor layer SC has a first part SC1, a second part SC2 and athird part SC3. The first part SC1 is located directly below the signalline S1. The first part SC1 extends along the second direction Y, andintersects the scanning line G1. The second part SC2 is located betweenthe signal line S1 and the signal line S2. The second part SC2 extendsalong the second direction Y, and intersects the scanning line G1. Thethird part SC3 extends along the first direction X, and connects thefirst part SC1 and the second part SC2.

The semiconductor layer SC is connected to the signal line S1 in athrough-hole CH1. The signal line S1 functions as a source electrode ofthe switching element SW. In addition, the semiconductor layer SC isconnected to the relay electrode RE in a through-hole CH2. The relayelectrode RE functions as a drain electrode of the switching element SW.The gate electrode GE1 corresponds to a part of the scanning line G1which overlaps the first part SC1. The gate electrode GE2 corresponds toa part of the scanning line G1 which overlaps the second part SC2.

The pixel electrode PE is located in an area surrounded by the scanninglines G1 and G2 and the signal lines S1 and S2. In addition, the pixelelectrode PE overlaps the scanning line G1, the relay electrode RE andthe through-hole CH2. In the illustrated example, the pixel electrode PEhas a substantially rectangular shape having long sides along the seconddirection Y, and is formed over substantially the entire pixel PX. Thepixel electrode PE is connected to the relay electrode RE in athrough-hole CH3. The through-hole CH3 overlaps a part of thethrough-hole CH2. That is, a part of the through-hole CH2 is locatedinside the through-hole CH3 in planar view. The through-holes CH1 to CH3have a square shape in FIG. 2 but may have a circular shape or a shaperounded at corners.

The through-hole CH3 has edges EG1 to EG4. In addition, the relayelectrode RE has edges EG11 to EG14. The edge EG1 overlaps the edgeEG11. As shown in FIG. 2, the edge EG2 overlaps the edge EG12. The edgeEG3 overlaps the through-hole CH2. The edge EG4 overlaps the scanningline G1.

FIG. 3 is a cross-sectional view of the display panel PNL along line A-Bshown in FIG. 2. The display panel PNL of the present embodimentcomprises a configuration corresponding a display mode using a lateralelectric field along the main surface of a substrate.

The first substrate SUB1 comprises an insulating substrate 10, theswitching element SW, insulating films 11 to 15, a capacitance electrodeCEL, the pixel electrode PE, a filling material (filler) 100, the commonelectrode CE, an alignment film AL1 and the like.

The insulating substrate 10 is a transparent substrate such as a glasssubstrate or a resin substrate. The switching element SW is located onthe insulating substrate 10. The switching element SW comprises the gateelectrodes GE1 and GE2, the semiconductor layer SC and the relayelectrode RE. The gate electrodes GE1 and GE2 are disposed on theinsulating substrate 10, and are covered with the insulating film 11.The semiconductor layer SC is disposed on the insulating film 11, and iscovered with the insulating film 12. The illustrated switching elementSW is a bottom-gate thin-film transistor where the gate electrodes GE1and GE2 are located closer to the insulating substrate 10 than thesemiconductor layer SC. It should be noted that the switching element SWmay be a top-gate thin-film transistor as will be described later. Thesignal line S1 and the relay electrode RE are disposed on the insulatingfilm 12. The signal line S1 and the relay electrode RE are in contactwith the semiconductor layer SC in the through-holes CH1 and CH2penetrating the insulating film 12, respectively.

The semiconductor layer SC is formed of, for example, polycrystallinesilicon. The gate electrodes GE1 and GE2, the relay electrode RE and thesignal line S1 are formed of a metal material such as aluminum (Al),titanium (Ti), silver (Ag), molybdenum (Mo), tungsten (W), copper (Cu)or chromium (Cr), an alloy of these metal materials combined together orthe like. The gate electrodes GE1 and GE2, the relay electrode RE andthe signal line S1 may have a single-layer structure or a multilayerstructure.

The insulating film 13 covers the switching element SW. The insulatingfilm 13 has the through-hole CH3 penetrating to the relay electrode RE.The edges EG3 and EG4 of the through-hole CH3 correspond to the edges ofthe bottom of the through-hole CH3. The edges EG3 and EG4 do not overlapthe edges EG13 and EG14 of the relay electrode RE. The edge EG3 islocated on the edge EG14 side with respect to the edge EG13. The edgeEG4 is located on the edge EG13 side with respect to the edge EG14. Thecapacitance electrode CEL is formed on the insulating film 13. Thecapacitance electrode CEL is located between the insulating film 13 andthe pixel electrode PE. The capacitance electrode CEL does not overlapthe through-hole CH3. The insulating film 14 covers the capacitanceelectrode CEL, and is also formed on the insulating film 13. A part ofthe insulating film 14 also extends inside the through-hole CH3. Thepixel electrode PE is formed on the insulating film 14. The pixelelectrode PE is in contact with the relay electrode RE in thethrough-hole CH3. Accordingly, a signal potential supplied to the signalline S1 is supplied to the pixel electrode PE via the relay electrodeRE.

The insulating film 15 covers the pixel electrode PE. The insulatingfilm 15 is also disposed inside the through-hole CH3, and also coversthe pixel electrode PE inside the through-hole CH3. In the illustratedexample, the insulating film 15 is also formed on the insulating film14. The through-hole CH3 is filled with the filling material 100. Thefilling material 100 is in contact with the insulating film 15 insidethe through-hole CH3. The filling material 100 protrudes toward thesecond substrate SUB2. As will be described later, the filling material100 may not protrude toward the second substrate SUB2. The fillingmaterial 100 is, for example, formed in the same process and of the samematerial as a spacer formed in the first substrate SUB1. The commonelectrode CE is formed on the insulating film 15. In addition, thecommon electrode CE covers the filling material 100. Furthermore, in oneexample, the common electrode CE has a plurality of openings OP. Theopenings OP each are opposed to the pixel electrode PE. The commonelectrode CE is covered with the alignment film AL1. The alignment filmAL1 is also disposed on the insulating film 15 in the openings OP. Inthe present embodiment, the relay electrode RE, the pixel electrode PE,the insulating film 15, the filling material 100, the common electrodeCE and the alignment film AL1 are stacked in this order at a positionoverlapping the through-hole CH3.

The insulating films 11, 12, 14 and 15 are formed of, for example, aninorganic insulating material such as silicon oxide, silicon nitride orsilicon oxynitride. The insulating film 13 is formed of, for example, anorganic insulating material such as polyimide. The capacitance electrodeCEL, the pixel electrode PE and the common electrode CE are formed of,for example, a transparent conductive material such as indium tin oxide(ITO) or indium zinc oxide (IZO).

In the present embodiment, the capacitance electrode CEL and the commonelectrode CE have the same potential. The pixel electrode PE has adifferent potential from the capacitance electrode CEL and the commonelectrode CE. In one example, a common potential which is common to eachpixel is supplied to the capacitance electrode CEL and the commonelectrode CE. The common potential may be a DC potential or an ACpotential. A signal potential corresponding to each pixel is supplied tothe pixel electrode PE. A fringing field for driving the liquid crystallayer LC is mainly formed by the pixel electrode PE and the commonelectrode CE opposed to each other via the insulating film 15. Acapacitance for holding the signal potential is formed by the pixelelectrode PE and the common electrode CE opposed to each other via theinsulating film 15 for sure, but is also formed by the capacitanceelectrode CEL and the pixel electrode PE opposed to each other via theinsulating film 14.

The second substrate SUB2 comprises an insulating substrate 20, alight-shielding layer 21, a color filter layer 22, an overcoat layer 23,a spacer SP and an alignment film AL2.

The insulating substrate 20 is a transparent substrate such as a glasssubstrate or a resin substrate. The light-shielding layer 21 and thecolor filter layer 22 are disposed on a side of the insulating substrate20 which is opposed to the first substrate SUB1. The light-shieldinglayer 21 is formed of, for example, resin colored in black, and delimitseach pixel PX. In the illustrated example, the light-shielding layer 21is opposed to the signal line S1, the switching element SW, thethrough-hole CH3 and the like. The overcoat layer 23 covers the colorfilter layer 22. The spacer SP is disposed on a side of the overcoatlayer 23 which is opposed to the first substrate SUB1. The spacer SP isarranged at a position overlapping the filling material 100. The fillingmaterial 100 abuts the spacer SP via the common electrode CE and thealignment films AL1 and AL2. The alignment film AL2 covers the overcoatlayer 23 and the spacer SP. It should be noted that the alignment filmAL2 may not be arranged on the first substrate SUB1 side of the spacerSP. Similarly, the alignment film AL1 may not be arranged on the secondsubstrate SUB2 side of the filling material 100.

The liquid crystal layer LC is located between the first substrate SUB1and the second substrate SUB2. The first substrate SUB1 and the secondsubstrate SUB2 are arranged such that the alignment film AL1 and thealignment film AL2 are opposed to each other. A predetermined cell gapis formed between the alignment film AL1 and the alignment film AL2 by aspacer which is not shown in the drawing. This cell gap is filled withthe liquid crystal layer LC.

FIG. 4 is a cross-sectional view of the first substrate SUB1 along lineC-D shown in FIG. 2. The illustration of the semiconductor layer SCbetween the insulating substrate 10 and the insulating film 11 isomitted in FIG. 4.

The through-hole CH3 has a width W11 in the first direction X. The relayelectrode RE has a width W12 in the first direction X. In the presentembodiment, the width W12 is less than or substantially equal to thewidth W11. Being “substantially equal” means that these widths areequal, or although the width W12 is slightly greater than the width W11,the difference is so slight that these widths can be regarded as equal.In the present embodiment, these widths are regarded as equal when thedifference between these widths is about ±1 μm. In the illustratedexample, the widths W11 and W12 are substantially equal, and the edgeEG1 overlaps the edge EG11 and the edge EG2 overlaps the edge EG12. Thewidth W11 of the through-hole CH3 is defined by the width of the bottomof the through-hole CH3. In addition, when the through-hole CH3 has acircular shape in a plane, the diameter is the width of the through-holeCH3.

FIG. 5 is a modification of the cross-sectional view of the firstsubstrate SUB1 along line C-D shown in FIG. 2. The configuration shownin FIG. 5 is different from the configuration shown in FIG. 4 in thatthe through-hole CH3 is shifted toward the signal line S1 with respectto the relay electrode RE.

In the modification, not only the relay electrode RE but also theinsulating film 12 are located inside the through-hole CH3. Therefore,the insulating film 14 is in contact with the insulating film 12 insidethe through-hole CH3. The edge EG1 of the through-hole CH3 is locatedcloser to the signal line S1 than the edge EG11 of the relay electrodeRE. In addition, the edge EG2 of the through-hole CH3 is located closerto the signal line S1 than the edge EG12 of the relay electrode RE.

The relay electrode RE has a corner CN1 on the signal line S1 side and acorner CN2 on the signal line S2 side. The corner CN1 is located insidethe through-hole CH3 without being covered with the insulating film 13.The corner CN2 is covered with the insulating film 13. In addition, thepixel electrode PE covers the corner CN1. The insulating film 15 is, forexample, disconnected at a position overlapping the corner CN1. Thepixel electrode PE is exposed from the disconnected part of theinsulating film 15. The filling material 100 covers the pixel electrodePE exposed at the corner CN1.

When the definition of the display device is increased, in order tomaintain a certain distance or more to prevent the occurrence of a shortcircuit between the relay electrode RE and the signal line S1 andbetween the relay electrode RE and the signal line S2, the width W12 ofthe relay electrode RE is set to substantially equal to or less than thewidth W11 of the through-hole CH3 in some cases. Therefore, if the relayelectrode RE and the through-hole CH3 are misaligned with each other,the corner CN1, that is, a step between the upper surface of the relayelectrode RE and the insulating film 12 is located inside thethrough-hole CH3, the insulating film 15 is disconnected by the step andcannot completely cover the pixel electrode PE. Consequently, the pixelelectrode PE and the common electrode CE formed on the pixel electrodePE via the insulating film 15 may be short circuited.

According to the present embodiment, the filling material 100 isinterposed between the pixel electrode PE and the common electrode CE atthe position overlapping the through-hole CH3. Therefore, even if thepixel electrode PE is exposed at the corner CN1, the pixel electrode PEand the common electrode CE are kept insulated from each other by thefilling material 100. Consequently, the occurrence of a short circuitbetween the pixel electrode PE and the common electrode CE can beprevented.

FIG. 6 is a cross-sectional view showing a detailed configurationexample of the relay electrode RE shown in FIG. 5.

The relay electrode RE has a first layer REA formed of titanium, asecond layer REB formed of aluminum, and a third layer REC formed oftitanium. Due to the difference in etching rate between the layers, whenthe relay electrode RE is etched, the second layer REB formed ofaluminum is reduced more than the first layer REA and the third layerREC formed of titanium. Therefore, the third layer REC protrudes morethan the second layer REB in some cases. The protruding part of thethird layer REC corresponds to the corner CN1. Consequently, thecoverage of the insulating film 15 is degraded in some cases. Even insuch a case, the occurrence of a short circuit between the pixelelectrode PE and the common electrode CE can be suppressed as describedabove.

FIG. 7 is a cross-sectional view showing the first modification of thefirst substrate SUB1. The configuration shown in FIG. 7 is differentfrom the configuration shown in FIG. 4 in that the width W12 of therelay electrode RE is less than the width W11 of the through-hole CH3.

In this modification, not only the relay electrode RE but also theinsulating film 12 are in contact with the insulating film 14 and thepixel electrode PE inside the through-hole CH3. The edge EG1 of thethrough-hole CH3 is located closer to the signal line S1 than the edgeEG11 of the relay electrode RE. In addition, the edge EG2 of thethrough-hole CH3 is located closer to the signal line S2 than the edgeEG12 of the relay electrode RE.

The corners CN1 and CN2 are located inside the through-hole CH3 withoutbeing covered with the insulating film 13. In addition, the pixelelectrode PE covers the corners CN1 and CN2. The insulating film 15 isdisconnected at, for example, positions overlapping the corners CN1 andCN2 (that is, steps) in some cases. However, even when the pixelelectrode PE is exposed from the disconnected parts of the insulatingfilm 15, the exposed pixel electrode PE is covered with the fillingmaterial 100. Therefore, the occurrence of a short circuit between thepixel electrode PE and the common electrode CE can be prevented.

Also in the first modification, the same effects as the above-describedembodiment can be obtained.

FIG. 8 is a cross-sectional view showing the second modification of thefirst substrate SUB1. The configuration shown in FIG. 8 is differentfrom the configuration shown in FIG. 7 in that the relay electrode RE islocated on the signal line S2 side.

The edge EG1 of the through-hole CH3 is located closer to the signalline S1 than the edge EG11 of the relay electrode RE. In addition, theedge EG2 of the through-hole CH3 overlaps the edge EG12 of the relayelectrode RE. The corner CN1 is located inside the through-hole CH3without being covered with the insulating film 13. In addition, thepixel electrode PE covers the corner CN1 inside the through-hole CH3,and also covers the surface of the insulating film 12. The otherconfiguration is the same as the configuration of FIG. 7, anddescription thereof is omitted.

Also in the second modification, the same effects as the above-describedembodiment can be obtained.

FIG. 9 is a cross-sectional view showing the third modification of thefirst substrate SUB1. The configuration shown in FIG. 9 is differentfrom the configuration shown in FIG. 3 in that the switching element SWis a top-gate thin-film transistor.

The insulating film 11 covers the insulating substrate 10. Thesemiconductor layer SC is located on the insulating film 11. Aninsulating film 11A covers the semiconductor layer SC. The gateelectrodes GE1 and GE2 are located on the insulating film 11A. Theinsulating film 12 covers the gate electrodes GE1 and GE2. The gateelectrodes GE1 and GE2 are located closer to the second substrate SUB2than the semiconductor layer SC. The through-holes CH1 and CH2 penetratethe insulating films 11A and 12 to the semiconductor layer SC.

Also in the third modification, the same effects as the above-describedembodiment can be obtained.

FIG. 10 is a cross-sectional view showing the fourth modification of thefirst substrate SUB1. The configuration shown in FIG. 10 is differentfrom the configuration shown in FIG. 3 in that the first substrate SUB1does not have the capacitance electrode CEL.

The pixel electrode PE is located on the insulating film 13. Inaddition, the pixel electrode PE is in contact with a side surface SS ofthe through-hole CH3. The insulating film 15 covers the pixel electrodePE, and is also in contact with the insulating film 13.

Also in the fourth modification, the same effects as the above-describedembodiment can be obtained.

FIG. 11 is a cross-sectional view showing the fifth modification of thefirst substrate SUB1. The configuration shown in FIG. 11 is differentfrom the configuration shown in FIG. 3 in that the filling material 100does not protrude toward the second substrate SUB2.

The filling material 100 has an upper surface 100A on the secondsubstrate SUB2 side. In addition, a part of the upper surface of thecommon electrode CE which is located between the openings OP is referredto as an upper surface CEA. The upper surface 100A is located closer tothe insulating substrate 10 than the upper surface CEA. At this time,the spacer SP of the second substrate SUB2 may abut the first substrateSUB1 at a position overlapping the filling material 100 or may beseparated from the first substrate SUB1.

Also in the fifth modification, the same effects as the above-describedembodiment can be obtained.

FIG. 12 is a plan view showing a configuration example of thecapacitance electrode CEL shown in FIG. 3. The illustration of the pixelelectrode PE shown in FIG. 2 is omitted in FIG. 12. In addition, theillustration of the common electrode CE shown in FIG. 13 is omitted.

Each capacitance electrode CEL overlaps the pixels PX arranged in thefirst direction X. More specifically, the capacitance electrodes CELeach extend along the first direction X, and are arranged at intervalsalong the second direction Y. The capacitance electrodes CEL are formedin a strip shape having a substantially constant width WE1. The widthWE1 is less than a pitch P1 of scanning lines G1 to G3 which areadjacent to each other. Here, the width WE1 and the pitch P1 are bothdefined along the second direction Y. The capacitance electrodes CELpartly overlap the scanning lines G1 to G3, signal lines S1 to S3, thesemiconductor layers SC and the relay electrodes RE, but does notoverlap the through-holes CH3. That is, the through-holes CH3 arrangedalong the first direction X are located between the capacitanceelectrodes CEL which are adjacent to each other along the seconddirection Y.

FIG. 13 is a plan view showing a configuration example of the commonelectrode CE shown in FIG. 3. The illustration of the pixel electrode PEshown in FIG. 2 is omitted in FIG. 13. In addition, the illustration ofthe capacitance electrode CEL shown in FIG. 12 is omitted.

The common electrode CE overlaps the pixels PX arranged along the firstdirection X and the second direction Y. In one example, the commonelectrode CE is formed of a single material. The common electrode CEoverlaps the relay electrodes RE and the through-holes CH3. The commonelectrode CE has the openings OP in the respective pixels PX. Oneopening OP overlaps one pixel electrode. The openings OP are locatedbetween the adjacent signal lines S1 to S3 and between the adjacentscanning lines G1 to G3. The openings OP do not overlap the relayelectrodes RE. In the illustrated example, each opening OP has a firstpart OPA extending in the second direction Y and a plurality of secondparts OPB extending in the first direction X. The second parts OPB arecontinuous with the first part OPA. Since the common electrode CE hasthe opening OP, an area where the common electrode CE and the pixelelectrode PE overlap each other is less than an area where thecapacitance electrode CEL and the pixel electrode PE overlap each other.

As described above, according to the present embodiment, a displaydevice capable of suppressing the reduction of display qualityassociated with the increase of definition can be obtained.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. A display device comprising: a first substrate;and a second substrate opposed to the first substrate, wherein the firstsubstrate comprises: an insulating substrate; a switching elementlocated on the insulating substrate and having a relay electrode; anorganic insulating film covering the switching element, and having afirst through-hole penetrating to the relay electrode; a pixel electrodelocated between the organic insulating film and the second substrate,and being in contact with the relay electrode via the firstthrough-hole; a first capacitance insulating film covering the pixelelectrode; a filler having an insulation property filled in at least thefirst through-hole, and located on the pixel electrode and the firstcapacitance insulating film; and a common electrode covering the filler.2. The display device of claim 1, further comprising a capacitanceelectrode located between the organic insulating film and the pixelelectrode, wherein the pixel electrode extends on the capacitanceelectrode, and the capacitance electrode does not overlap the firstthrough-hole.
 3. The display device of claim 2, wherein a same potentialas the common electrode is supplied to the capacitance electrode.
 4. Thedisplay device of claim 1, wherein a width of the relay electrode issubstantially equal to a width of the first through-hole.
 5. The displaydevice of claim 1, wherein a width of the relay electrode is less than awidth of the first through-hole.
 6. The display device of claim 1,wherein the filler protrudes toward the second substrate.
 7. The displaydevice of claim 1, wherein the second substrate comprises a spacerprotruding toward the first substrate at a position overlapping thefiller, wherein the filler supports the spacer via the common electrode.8. The display device of claim 1, wherein the second substrate comprisesa spacer protruding toward the first substrate at a position overlappingthe filler, and a part of the common electrode which is located on thefiller abuts the spacer.
 9. The display device of claim 1, wherein theswitching element has a semiconductor layer, and a gate electrodelocated closer to the insulating substrate than the semiconductor layer.10. The display device of claim 1, wherein the switching element has asemiconductor layer, and a gate electrode located closer to the secondsubstrate than the semiconductor layer.
 11. The display device of claim1, further comprising an inorganic insulating film being in contact witha lower surface of the relay electrode, wherein a step between the relayelectrode and the inorganic insulating film is disposed inside the firstthrough-hole.
 12. The display device of claim 1, wherein the switchingelement comprises a semiconductor layer connected to the relay electrodein a second through-hole, and a part of the second through-hole islocated inside the first through-hole in planar view.
 13. The displaydevice of claim 1, wherein the common electrode is opposed to the pixelelectrode via at least the filler in the first through-hole, and isopposed to the pixel electrode via at least the first capacitanceinsulating film in other than the first through-hole.
 14. The displaydevice of claim 13, wherein the common electrode and the pixel electrodeare located such that a first distance therebetween in the firstthrough-hole is larger than a second distance therebetween in other thanthe first through-hole.
 15. The display device of claim 1, wherein thecommon electrode and the insulating substrate are located such that athird distance therebetween in the first through-hole is larger than afourth distance therebetween in other than the first through-hole.
 16. Adisplay device substrate comprising: an insulating substrate; aswitching element located on the insulating substrate and having a relayelectrode; an organic insulating film covering the switching element,and having a first through-hole penetrating to the relay electrode; apixel electrode located farther from the insulating substrate than theorganic insulating film, and being in contact with the relay electrodevia the first through-hole; a first capacitance insulating film coveringthe pixel electrode; a filler having an insulation property filled in atleast the first through-hole, and located on the pixel electrode and thefirst capacitance insulating film; and a common electrode covering thefiller.
 17. The display device substrate of claim 16, further comprisinga capacitance electrode located between the organic insulating film andthe pixel electrode, wherein the pixel electrode extends on thecapacitance electrode, and the capacitance electrode does not overlapthe first through-hole.
 18. The display device substrate of claim 17,wherein a same potential as the common electrode is supplied to thecapacitance electrode.
 19. The display device substrate of claim 16,wherein a width of the relay electrode is substantially equal to a widthof the first through-hole.
 20. The display device substrate of claim 16,wherein a width of the relay electrode is less than a width of the firstthrough-hole.
 21. The display device substrate of claim 16, wherein thefiller protrudes toward the opposite side of the insulating substrateside.
 22. The display device substrate of claim 16, wherein theswitching element has a semiconductor layer, and a gate electrodelocated closer to the insulating substrate than the semiconductor layer.23. The display device substrate of claim 16, wherein the switchingelement has a semiconductor layer, and a gate electrode located theopposite side of the insulating substrate side of the semiconductorlayer.
 24. The display device substrate of claim 16, further comprisingan inorganic insulating film being in contact with a lower surface ofthe relay electrode, wherein a step between the relay electrode and theinorganic insulating film is disposed inside the first through-hole. 25.The display device substrate of claim 16, wherein the switching elementcomprises a semiconductor layer connected to the relay electrode in asecond through-hole, and a part of the second through-hole is locatedinside the first through-hole in planar view.
 26. The display devicesubstrate of claim 16, wherein the common electrode is opposed to thepixel electrode via at least the filler in the first through-hole, andis opposed to the pixel electrode via at least the first capacitanceinsulating film in other than the first through-hole.
 27. The displaydevice of claim 26, wherein the common electrode and the pixel electrodeare located such that a first distance therebetween in the firstthrough-hole is larger than a second distance therebetween in other thanthe first through-hole.
 28. The display device of claim 16, wherein thecommon electrode and the insulating substrate are located such that athird distance therebetween in the first through-hole is larger than afourth distance therebetween in other than the first through-hole.